Telemetric system



Au .-13, 1940. J. D. RYDER 2,211,711

TELEMETRIC SYS-TEM.

Filed May 28, 1957 3 Sheets-Sheet 1 5 &cl I 23 I as W 56 3m ent or F 2 JOHN D. RYDER Aug. 13, 1940... J. D7 RYDER 2,211,711

TELEMETRIC SYSTEM Filed May 28, 1937 s Sheets-Sheet 2 Zhwentor I JOHN D. RYDER 1' M1 4 9/ attorney Aug. 13, J. D. RYDER I I TE LEMETRIC SYSTEM Filed May 28, 1937 3 Sheets-Sheet ,3

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lnventor N JOHN D- RYDER f r 9 v Patented Aug. 13, 1940 UNITED STATES PATENT OFFICE TELEMET'RIG SYSTEM John D. Ryder, University Heights, Ohio, assignor to Bailey Meter Company, a corporation Delaware Application May 28,

8 Claims.

maintain the transmitting and receiving impulses of equal time length.

One feature of my invention resides in the mechanism employed at the transmitting and receiving stations whereby the electric circuits for originating the electric impulses are closed through individual contacts, but simultaneously opened through a common switch.

A further feature resides in the mechanical linkage employed at the transmitting and receiving stations whereby angularity is eliminated and movements of the indicator at all times agree precisely with movements of the device sensitive to the variable.

Still another feature resides in the simple means provided for maintaining the cyclically operable means employed at the transmitter and receiver for originating the electric impulses in exact phase.

A further feature resides in the means provided for eliminating the effects of back lash on such cyclically operable means as may be present in the gear reduction incorporated in the driving mechanisms therefor.

In the drawings:

Fig. 1 illustrates in somewhat diagrammatic fashion, a transmitting mechanism.

Fig. 2 illustrates in similar manner, a receiving mechanism.

Fig. 3 is a wiring diagram of of Figs. 1 and 2.

Figs. 4, 5 and 6 are details of cams of Figs. 1 and 2.

Fig. 7 is a wiring diagram for one transmitter and two receivers.

Referring to Fig l, I have shown a transmitting station in which is a spindle l angularly the arrangements the variable, the magnitude of which it is desired to remotely indicate; record or otherwise exhibit.

U positioned by a device (not shown) responsive to" 1937, Serial No. 145,217

and varying in known relation to the rate of fluid flow therethrough, or it may be positioned by a Bourdon tube sensitive to pressure or temperature. In other instances it maybe positioned manually, so that commands, orders, or other intelligence may be transmitted to the receiving station. I

Secured to the spindle I is an index 2, which in cooperation with a suitably graduated scale 3 gives an indication of the magnitude of the variable at the transmitting station. Likewise secured to the spindle l is an arm 4 pivotally connected through a link 5 to a transmitting arm 6 angularly positionable about a shaft 1. Angular movements of the spindle l are, therefore, mechanically transmitted to the arm 6. Also mounted on the shaft 1 is a member 8 having a projection 9 normally resting by gravity on the arm 6. As the arm 6 is positioned about the shaft 1 the member 8 is also positioned through the agency of the projection 9.

Carried by the member 8 is a contact in arranged to engage a cooperating contact ll secured to a plate I2 mounted on a follower arm l3, one end of which is pivotally supported by the shaft 1. The opposite end of the follower I3 is provided with a pin on which is rotatably mounted a cam follower I4 engaging the contour of a cam I5, continuously rotated in the direction of the arrow by a synchronous motor I6 through a shaft 11. The motor I6 is energized through a field winding I8 which may be connected to any suitable source of alternating current and is provided with an integral gear reduction unit l9, so that the shaft l'l rotates at a relatively low speed.

The follower l3, through the cam I5, is periodically oscillated between predetermined limits. At some point in its travel, depending upon the position of the arm 6, the member 8 is picked up and carried to the upper travel limit, whence the member 8 is returned to its normal position when the extension 9 engages the arm 6. The rising section of the cam I5 designated by the angle A in Fig. 1 is substantially uniform, so that the increment of time during which the contact I0 is in engagement with the contact II while the follower 14 engages this section of cam l5 bears a functional relation to the magnitude of the variable angularly positioning the spindle I.

In Fig. 2 is shown a receiving station in some respects similar to the transmitting station in which is an index 20 pivotally supported by a shaft 2| and cooperating with a suitably graduated scale 22 to remotely indicate the magnitude of the variable angularly positioning the spindle I. The index 29 is positioned by a reversible motor 23 having opposed wound split shading poles 24 and 25. If the pole 24 is short circuited the motor 23 rotates in one direction. If the pole 25 is short circuited the motor rotates in the opposite direction. With both poles simultaneously energized or deenergized the motor is not urged to rotation. The motor 23 is provided with a gear reduction 28 so that a crank arm 21 positioned by the output shaft of the gear reduction moves through a relatively small angle for a large angular motion of the motor.

The crank arm 21 positions the index 29 through a receiving arm 28 pivoted on a shaft 29 and provided with a slot 39. A block 3| adjustable radially with respect to the shaft 29 by a screw 32 is guided in the slot 39 and is pivotally connected to a link 33 likewise pivotally connected to the index 29. Movement of the block 3| toward the shaft 29 serves to decrease the angular motion of the index 29 for a given angular motion of the crank 21. Con- -versely movement of the block 31 away from the shaft 29 serves to increase the movement of the index 29 for a given movement of the crank 21. Through the agency of this adjustment any desired angular travel of the index 29 may be obtained for a given angular travel of the index 2.

The receiving arm 28 is provided with an extension 34 upon which normally rests by gravity an extension 35 of a member 39 movably mounted on the shaft 29. Carried by the member 36 is a contact 31 arranged to engage a cooperating contact 38 secured to a plate 39 mounted on a follower arm 49 pivoted about the shaft 29. The arm 49 through a rotatable follower 4| is periodically oscillated between predetermined limits by a cam 42 continuously rotated by a self-starting synchronous motor 43 through a shaft 44. The motor 43 is similar to the motor is and is provided with an integral gear reduction 45 so that cams l5 and 42, identical in contour, rotate in synchronism with each other. The cam 42 is provided with a rising section A similar to section A of cam I5, so that the increment of time during which contact 31 is in engagement with contact 38, while the follower 41 engages section A bears a functional relation to the position of the index 29.

Referring to Fig. 3, the transmitter is generally indicated at 59 and the receiver at 5|. When contacts.l9, ll engage, the pole winding 24 of motor 23 is short circuited, thereby tending to produce rotation in one direction. Similarly when contacts 31, 38 engage, winding 25 of motor 23 is short circuited, tending to produce rotation in the opposite direction. When the position of index 29 agrees with that of index 2, contacts l9, II and 31, 39 engage at the same instant and motor 23 remains stationary. If the index 2 is positioned downwardly a predetermined amount by the spindle I, then contacts l9, II will engage prior to engagement of contacts 31, 38 and motor 23 will rotate in a direction to position the receiving arm 28 in a clockwise direction; so that index 29 is positioned downwardly. Until indices 2 and 29 are brought into proper correspondence contacts l9, II will continue to engage prior to contacts 31, 38 and during each cycle of operation motor 23 will -operateto position the receiving arm'28 in a clockwise direction until proper correspondence is restored. Conversely, if the index 2 is posi- The windings 24, 25 are shown connected to a I common neutral 52, in which is located a mercury switch 53. As shown in Figs. 2 and 3 the mercury switch 53 is in closed position. However, upon the follower 49 being positioned upwardly to the termination of the cam section A the mercury switch 53 is thrown to open position, thereby simultaneously open circuiting the windings 24, 25 notwithstanding that contacts I9, II and 31, 38 remain engaged. As shown in Fig. 2 the mercury switch 53 is pivotally supported on a shaft 54 mounted in a stationary bracket 55. Likewise supported on the shaft 54 is a beam 56 pivotally connected to the arm 49 through a link 51. Mounted in the base of the mercury switch 53 are adjustable screws 69 and GI arranged to engage the beam 56. The screws 69 and BI are adjusted so that upon the mercury switch 53 being thrown to open position it will remain open until the follower approaches the origin of the rising section A when it is restored to the closed position, so that windings 24 and 25 will be energized upon engagement of contacts l9, II and 31, 38 respectively.

It is apparent from the foregoing description of the operation of mercury switch 53 that the shape of cams l5 and 42 after the terminus of rising sections A and A respectively are passed has no effect upon the operation of motor 23, for regardless of when the contacts 19, II and/or 31, 38 disengage the motor remains stationary as the neutral has been opened. The windings 24, 25 are therefore only short circuited through contacts 19, II and 31, 38 respectively, whereas they are open circuited through mercury switch 53. As known, contacts such as I 9, l l and 31, 38 when used to deenergize a circuit may cause sparking, which is not only injurious to the contacts but, if surrounded by an explosive atmosphere, may cause serious explosions. Engagement of contacts l9, II and 31, 38 energizing the windings 24 and 25 creates negligible sparking. The mercury switch 53 is confined within a controlled atmosphere so that sparking occurring therein in no way disturbs the operation of the system or gives rise to explosion hazards.

As hereinbefore stated, cams l5 and 42 operate in synchronism and in exact phase, so that the point on the contour of cam 42 engaged by follower 4i agrees exactly with the point on the contour of cam 15 engaged by follower I4. When initially placing the device in operation, or after a power failure, a phase displacement between cams l5 and 42 may exist. To restore the desired phase I provide means for comparing the position of cam 42 once each revolution with the position of cam l5, and if displaced therefrom retarding the motor 43 until proper phase is restored. Once restored cams I5, 42 will remain in phase inasmuch as in the preferred embodiment they are driven by similar snychronous motors.

The motor 43 is normally energized through closed contacts 62, 63. A bracket 64 supports the contact 62, whereas the contact 63 is carried by a member 65 pivotally mounted on the shaft 29. Once each revolution of the cam 42 an extension 66 on the arm 46 engages a laterally extending lip 61 on cam 42. Such engagement causes the roller 4| to be raised above the cam 42 and for an anvil 68 to engage an adjustable screw 69 carried by the member 65. The member 65 is then oscillated about shaft 29 sufficient to cause disengagement of contacts 62, 63, thereby opening the circuit normally energizing the motor 43. v

Connected in parallel with contacts 62, 63 are contacts 10, 1|. The contact 16 is carried by the plate l2, whereas the contact 1| is carried by a member 12 pivotally' mounted on shaft 1 and normally supported at the opposite end by an adjustable screw 13 carried by a fixed bracket 14. The member |3 is provided with a projection 15 arranged to engage a lip.16 on cam I5. Engagement of the projection 15 with the-lip 16 raises the member I3 sufficiently so that contact 10 engages contact 1|,,thereby serving to energize the motor 43.

If cams I5, 42 are in phase, contacts 18, 1| will engage at the instant contacts 62, 63 disengage, and contacts 62, 63 will reengage at the instant contacts 10, 1| disengage, thereby effecting continuous energization of the motor 43. Should the cam 42 lead the cam l5, contacts 62, 63 will open before contacts 10, 1| engage and the motor 43 will be deenergized for a short .interval each revolution of cam 42, retarding the same a small amount at each operation until the opening of contacts 62, 63 occurs at the instant .contacts 18, II close and cams 42, I are brought into phase. If cam 42 lags cam I5, contacts 62, 63 will remain open after the contacts 16, 1| have disengaged, interrupting the receiver motor circuit every revolution until cam 42 is sufiiciently retarded so that motor 43 will not coastto a closed position of contacts 62, 63. Cam 42 will then be stationary for one revolution of cam l5, or until contacts 10, 1| again close, at which time the motor 43 will be energized and cam 42 will lead cam |5. Thereafter motor 43 will be deenergized for a short interval in each'revolution of cam 42 until proper phase relationship is again restored.

In Fig. 4 I have shown the cam 42 and associated parts in the position occupied at the beginning of the phasing operation. The projection 66 isin engagement with the lip 61 and roller 4| is raised from cam 42. At approximately this instant as determined by the adjustment of screw 69 contact 62 disengages contact 63. In the transmitter, if cams 42 and I5 are in phase, at this same instant cam 5 and associated parts occupy the same relative positions as shown in Fig. 4, and contacts 16, 1| engage. observed that atthis instant when roller 4| leaves cam "its center is still to the right of radial edge 11 of cam 42. With cam 42' rotating in the direction of the arrow it is apparent that any backlash present in gear reduction unit 45, would upon roller 4| rolling over edge 11, cause cam 42 to jump forward. By providing that the roller 4| is lifted from the contour of cam 42 before its center is on a radial line with edge 11 such It will be extension 66 is just about to drop over edge 11.

' The follower 4| will fall to a constant radius section B, as shown clearing entirely the edge 11.

Theradial edge 11 forming a sheer drop to the constant radius section B provides a means for disengaging contacts 62, 63 at an exact 'point in the angular travel of cam 42, thereby facilitating of constant radius section B to the origin of the rising section A, and serves to carry member 40 to its initial or starting. position.

Cam I5 is identical with cam 42, an edge 18 forming a sheer drop to a constant radius section B, which 'is followed by a falling section C extending to the origin of rising section A. The operation therefore of cam l5 and associated parts is exactly similar to that described with reference to cam 42 and illustrated in Figs. 4 and 5.

As previously described, mercury switch 53 is thrown to open position at the terminus of section A of cam 42. The exact location of the terminus of section A is unimportant so long as it occurs before projection 66 engages lip 61. It will be observed that during phasing operation, therefore, motor 23 is deenergized so that if because cams l5 and 42 are out of phase motor 43 is stopped momentarily or for one revolution of cam I5, incorrect positioning of index will not occur.

Referring now to Fig. 7 I have therein shown a single transmitter 80 arranged to control a plurality of receiving stations generally indicated at 8| and 82. I have shown two receiving stations coupled with a single transmitting station merely for purposes of illustration and it will be obvious from the following description that a single transmitting station may be coupled with any number of receiving stations located remotely therefrom and from each other.

The mechanism within transmitting station 80 is identical with that shown in Fig.1 and the mechanism Within the receiving'stations 8| and 82 is identical with that shownin Fig. 2. Within the receiving stations 8| and 82 are reversible motors 83 and 84 respectively, corresponding to motor 23. The motor 83 has opposed windings 85 and 86 respectively, whereas motor 84 has opposed windings 81 and 88. Windings 86 and 88 are periodically energized through closure of contacts 89 and 98 respectively, periodically oscillatedby motors 9| and 92, corresponding to motor 43. Opposed windings 85, 81 are connected in series with each other and with the primary of a transformer 93. The secondary of the trans-- former 93 is periodically short circuited by contacts 94 closed by motor 95 correspondingly to motor I6 in Fig. 1.

In-operation contacts 89 and 98 are periodically closed for increments of time depending upon the position of the indices (not shown) moved by motors 83 and 84 respectively. Concurrently therewith windings 85 and 81 are simultaneously energized through closure of contacts 94. The increment of time during which contacts94 are closed is, as hereinbefore described, dependent upon the magnitude of the variable being measured. Through the agency of the transformer 93 the potential across the contacts 94 may be maintained at a relatively low value when normal potential exists across windings and 87.

Included in the neutral winding of motors 83 and 84 are mercury switches 96 and 91 respectively, periodically thrown to open position as described with reference to mercury switch 53 shown in Fig. 2.

To main .aim motors 9| and 92 in proper phase relationship with 'motor 95 I show within receiving station 8| normally closed contacts 98 and within receiving station 82 normally closed contacts 99, corresponding to contacts 62, 63 as shown in Fig. 2. Periodically contacts 98, 99 are open circuited. Simultaneously contacts I00 within transmitter station 80 engage, serving to maintain continuous energization of motors 9| and 02 if they are in proper phase relationship with motor 95.

Connected in parallel with contacts 98 across motor 9| is the primary of a transformer IIIIIA, the secondary of which is connected in the output circuit of an electron discharge device NH. The grid I02 is normally biased through a transformer I03 to maintain the output circuit deenergized. Closure of contacts I00 acts, however, to change the grid bias and render the electron discharge device IOI conducting, thereby reducing the impedance of the primary of the transformer IO0A sufficiently so that motor 9| is energized. Accordingly, if operation of contacts 98 and I00 ocour in proper sequence motor 9| will be continuously energized. If however due to lack of proper phase such sequential operation does not occur, the motor 9| will be retarded until proper phase relationship with respect to motor 95 is restored.

Within receiving station 82 is a similar arrangement for maintaining proper phase relationship be ween motors 92 and 95. Connected in parallel with the contacts 99 across motor 92 is the primary of a transformer I04, the secondary of which is connected in the output circuit of an electron discharge device I05, having a grid I06. Normally biased by means of a transformer I01 to render the output circuit non-conducting. The grid I06 is connected in parallel with grid I02 across contacts I00. Closure of contacts I00 acts therefore to simultaneously change the bias of grid I06, as Well as grid I02. The change in bias of grid I06 serves to reduce the impedance of the primary winding of transformer I04 sufficiently so that motor 92 is energized.

Normally, therefore, motors 9| and 92 are energized by contacts 98 and- 99 respectively. Periodically these contacts disengage, so that if motor 9| or motor 92 is not in phase with motor 95 it is retarded. Normally, however, contacts I00 will engage during the increment of time contacts 98 and 99 are disengaged, so that motors 9| and 92 are continuously energized.

While I have described my invention and preferred embodiments thereof, I desire it to be understood that I am not to be limitedthereby except as to the claims in view of the prior art.

Certain portions of my invention, disclosed but not claimed herein, is disclosed and claimed in my divisional application Serial No. 317,833 filed February 8, 1940 and co-pendlng.

What I claim as new, and desire to secure by Letters Patent of the United States, is:

1. In a telemetric system, in combination, a transmitter comprising a shaft, a transmitting arm angularly positioned about said shaft in accordance with the magnitude of a variable, a contact member pivoted on said shaft and normally resting on said transmitting arm, a cam, a follower member pivotally mounted on said shaft and engaging said cam, a motor for continuously rotating said cam whereby said follower member is cyclically oscillated through a predetermined course, contact means carried by said follower member moved into engagement with said contact member and carrying said contact member through a portion of said course dependent upon the position of said transmitting arm, and an electrical circuit controlled by the engagement of said contact means and contact member.

2. In a telemetric system, in combination, a transmitter comprising a shaft, a transmitting arm angularly positioned about said shaft in accordance with the magnitude of a variable, a contact member pivotally mounted on said shaft and normally resting on said transmitting arm, a cam having a rising and a falling section, a follower member having one end pivotally mounted on said shaft and the other engaging said cam,

a motor for rotating said cam to periodically reciprocate said follower member through a predetermined cyclic course, and carry said contact member through a portion of said cyclic course determined by the position of said transmitting arm, an electric circuit, means for closing said circuit actuated upon engagement of said follower and contact members, and means operated by said follower member for opening said circuit before said contact and follower members disengage.

3. In a telemetric system, in combination, a transmitter comprising a shaft, a transmitting member angularly positioned about said shaft in accordance with the magnitude of the variable, a contact member mounted on said shaft and normally resting on said transmitting member, cyclically operable means for periodically oscillating said contact member about said shaft from said normal position of rest to a predetermined position and returning said member to engagement with said transmitting member, an electric circult energized by engagement of said contact member and cyclically operable means operated by said cyclically operable means, and means for deenergizing said circuit before said contact member and cyclically operable means disengage.

4. In a telemetric system, in combination, a transmitter comprising a shaft, a transmitting member angularly positioned about said shaft in accordance with the magnitude of a variable, a contact member pivotally mounted on said,shaft and normally resting on said transmitting arm, cyclically operable means for periodically oscillating said contact member about said shaft from said normal position of rest to a predetermined position and returning said member to said normal position, a receiver comprising a reversible motor having opposed windings, a shaft, a receiving arm angularly positioned about said shaft by said motor, a contact member pivotally mounted on said shaft and normally resting on said receiving arm, cyclically operable means for periodically oscillating said contact member about said shaft from said normal position to a predetermined position and returning said contact member to said normal position, means for energizing one of the windings of said motor when said contact member in said transmitter is moved from said normal position, means for energizing the opposed winding when said contact member in said receiver is moved from said normal position, and means under the control of one of said said cyclically operable means for simulv taneously deenergizing said windings before windings urging said motor to operation in one direction, energization of the other of said windings urging said motor to operation in opposite direction, an electric circuit connecting one winding of each of said motors in series, a transformerhaving a primary winding connected in said circuit, means under the control of said transmitting station for periodically short circuiting the secondary of said transformer for increments of time in accordance with the magnitude of a variable to energize all of said last named windings simultaneously, and means under the control of each of said receiving stations for periodically energizing the other winding of the motor associated therewith.

6. In a telemetric system, a transmitting station and a plurality of receiving stations, a motor having opposed windings located in each of said receiving stations, energization of one of said windings urging said motor to operation in one direction, energization of the other of said windings urging said motor to operation in opposite direction, an electric circuit connecting a winding of each of said motors in series, means under the control of said transmitting station for energizing said circuit, and means under the control of each of said receiving stations for energizing the other winding of the motor located therein.

7. In a telemetric system, a transmitting station and a'plurality of receiving stations, a motor ondary of said transformer for increments of time proportional to the magnitude of a variable to energize all of said windings simultaneously, and means under the control of each of said members for energizing the other winding of the motor associated therewith for increments of time proportional to its position.

8. In a telemetric system, in combination, a transmitter comprising a shaft, a transmitting member angularly positioned about said shaft in accordance with the magnitude of a variable, a

contact member mounted on said shaft and normally resting on said transmitting member, a first cyclically operable means for periodically oscillating said contact member about said shaft from said normal position of rest to a predetermined position and returning said member to engagement with said transmitting member, an electric circuit energized by engagement of said contact member and cyclically operable means, a second cyclically operable means, and means operated by said second cyclically operable means for deenergizing said circuit before said'contact member and cyclically operable means disengage.

'JOHN D. RYDER. 

